Recovery of copper from chalcopyrite utilizing copper sulfate leach

Abstract

Copper is recovered from chalcopyrite by means of a pollution-free hydrometallurgical process which entails leaching and converting the chalcopyrite with copper sulfate in order to produce an insoluble copper sulfide, a soluble iron sulfate and sulfuric acid. A secondary leach is then conducted in order to react the copper sulfide with oxygen in the presence of a jarosite-forming cation to produce a soluble copper sulfate and an insoluble iron bearing jarosite. This copper sulfate is separated from the jarosite and sent to a copper recovery process and/or recycled. Alternatively, the copper sulfide from the initial leach may be separated from the iron sulfate solution immediately after the initial leach, and this copper sulfide can be treated with other processes to produce elemental copper and sulfur.

What is claimed is: 
     
       1. A process for hydrometallurgically recovering elemental copper from chalcopyrite comprising: reacting the chalcopyrite with a copper sulfate solution at a temperature and mole ratio sufficient to form an insoluble copper sulfide consisting essentially of digenite, a soluble iron sulfate and sulfuric acid;   separating the copper sulfide from the iron sulfate; and   recovering the elemental copper from the copper sulfide.   
     
     
       2. The process of claim 1 wherein the concentration of the copper sulfate solution is from about 30 to about 100 grams per liter of copper. 
     
     
       3. The process of claim 1 wherein the chalcopyrite reaction is conducted from about 180°C to about 200°C. 
     
     
       4. The process of claim 1 wherein the mole ratio of copper sulfate to chalcopyrite reactants is at least about two to one. 
     
     
       5. The process of claim 4 wherein the temperature of the copper sulfate reaction is maintained from about 180°C to about 200°C. 
     
     
       6. A process for hydrometallurgically recovering copper from chalcopyrite comprising: initially leaching the chalcopyrite with a copper sulfate solution at a temperature and mole ratio sufficient to form insoluble digenite, minor amounts of other insoluble copper sulfides and a soluble iron sulfate;   separating the insoluble copper sulfides from the soluble iron sulfate;   secondarily leaching the copper sulfides with oxygen in an acid medium and in the presence of a jarosite forming cation to form a soluble copper sulfate solution and an insoluble jarosite; and   recovering a portion of the copper from the copper sulfate solution and recycling the remainder of the copper sulfate solution to the initial leach reaction.   
     
     
       7. The process of claim 6 wherein the mole ratio of copper sulfate to chalcopyrite reactants is at least about two to one. 
     
     
       8. The process of claim 6 wherein the temperature of the copper sulfate reaction is maintained from about 180°C to 200°C. 
     
     
       9. A process for hydrometallurgically recovering copper from chalcopyrite comprising: leaching and converting the chalcopyrite with a copper sulfate solution at a temperature and mole ratio sufficient to concurrently form a mixture of an insoluble copper sulfide consisting essentially of digenite, a soluble iron sulfate and sulfuric acid;   subjecting said concurrently formed mixture to a secondary treatment including leaching with oxygen and addition of a jarosite-forming cation, to produce from said concurrently formed mixture a soluble copper sulfate solution and an insoluble jarosite;   separating the soluble copper sulfate solution from the insoluble jarosite; and   recovering elemental copper from the copper sulfate solution.   
     
     
       10. The process of claim 9 wherein a portion of the copper sulfate solution produced from the secondary leaching operation is recycled to treat fresh chalcopyrite feed material. 
     
     
       11. The process of claim 9 wherein the leaching of the chalcopyrite with copper sulfate is performed at a temperature of from about 180°C to about 200°C. 
     
     
       12. The process of claim 9 wherein elemental copper is recovered by means of electrolysis. 
     
     
       13. The process of claim 9 wherein the jarosite-forming cation is sodium. 
     
     
       14. The process of claim 9 wherein the jarosite-forming cation is potassium. 
     
     
       15. The process of claim 9 wherein the jarosite-forming cation is an ammonium ion. 
     
     
       16. The process of claim 9 wherein the chalcopyrite initially treated with the copper sulfate solution is in the presence of other mixed sulfides. 
     
     
       17. The process of claim 9 wherein the mole ratio of copper sulfate to chalcopyrite reactants is at least about two to one. 
     
     
       18. The process of claim 9 wherein the temperature of the copper sulfate reaction is maintained from about 180°C to 200°C. 
     
     
       19. A process for hydrometallurgically recovering elemental copper from chalcopyrite comprising: reacting the chalcopyrite with a copper sulfate solution at a temperature and mole ratio sufficient to form an insoluble copper sulfide consisting essentially of digenite, a soluble iron sulfate and sulfuric acid;   separating the copper sulfide from the iron sulfate;   leaching the separated copper sulfide with a chloride selected from the group consisting of ferric chloride and cupric chloride in order to produce a solution comprising cuprous chloride, cupric chloride and ferrous chloride; and   reducing at least a portion of the cuprous chloride to elemental copper.   
     
     
       20. The process of claim 19 wherein the chalcopyrite reaction is conducted from about 180°C to about 200°C. 
     
     
       21. The process of claim 20 wherein the mole ratio of copper sulfate to chalcopyrite reactants is at least about two to one. 
     
     
       22. The process of claim 19 wherein the solution comprising cuprous chloride, cupric chloride and ferrous chloride is subjected to electrolysis to produce elemental copper. 
     
     
       23. A process for hydrometallurgically recovering elemental copper from chalcopyrite comprising: reacting the chalcopyrite with copper sulfate solution at a temperature and mole ratio sufficient to form an insoluble copper sulfide consisting essentially of digenite, a soluble iron sulfate and sulfuric acid;   separating the copper sulfide form the iron sulfate;   leaching the separated copper sulfide with an ammoniacal leach solution; and   recovering copper from the ammoniacal leached solution.   
     
     
       24. The process of claim 23 wherein the chalcopyrite reaction is conducted from about 180°C to about 200°C. 
     
     
       25. The process of claim 24 wherein the mole ratio of copper sulfate to chalcopyrite reactants is at least about two to one.